The dulcimer is at heart a folk instrument, so it uses simple scaling. Musically the scale is called "diatonic," which means that it features only the white keys of a piano. Sharps and flats are left out.

Modern dulcimers, however, usually have one extra fret after the sixth diatonic fret.

The extra fret is most often called the "six and a half" fret, but we'll just label it as fret 7 on this site. This fret is used by many songs in many musical styles, and it allows playing in two different keys (D and G) without re-tuning. It's a little confusing at first, but the added versatility is well worth it.

You can try out the extra fret by playing the following scales. Press the bottom string just behind each numbered fret and pluck the string (0 means no fret is used).